Exam 3 Biology

What is photosynthesis?

The use of sunlight to manufacture carbohydrates.

What type of organisms perform photosynthesis?

Autotrophs (self-feeders).

What are heterotrophs?

Organisms that cannot perform photosynthesis and obtain energy from other sources.

What does photosynthesis convert?

Electromagnetic energy to chemical energy.

What are the requirements for photosynthesis?

Sunlight, carbon dioxide (CO2), and water (H2O).

What is produced as a byproduct of photosynthesis?

Oxygen (O2).

Is photosynthesis an exergonic or endergonic process?

Endergonic.

Where does photosynthesis occur?

In the chloroplasts of green plants, algae, and other photosynthetic organisms.

What are thylakoids?

Flattened, vesicle-like structures inside chloroplasts that form stacks called grana.

What is the equation for photosynthesis?

6CO2 + 6H2O + light -> C6H12O6 + 6O2.

What is the main function of the light reaction in photosynthesis?

To create a proton electrochemical gradient used to synthesize ATP and produce NADPH.

What are the main types of phosphorylation?

Substrate level phosphorylation and oxidative phosphorylation.

What is the cell cycle?

The series of events that take place in a cell leading to its division and duplication.

What are the two types of cell division?

Mitosis and meiosis.

What does mitosis produce?

Somatic cells that are genetically identical to the parent cell.

What does meiosis produce?

Gametes (reproductive cells) that are genetically different.

What is a chromosome?

A structure of DNA that encodes the cell's genetic information.

What is chromatin?

DNA plus histone proteins in an unwound state.

What is a gene?

A section of DNA that codes for a specific RNA or protein.

What happens during anaphase of mitosis?

Sister chromatids are pulled apart to opposite ends of the cell.

What is the role of the mitotic spindle?

To separate sister chromatids during mitosis.

What occurs during telophase?

The nuclear envelope reforms around chromosomes, and chromosomes uncoil.

What is the significance of cell cycle checkpoints?

They regulate cell division and prevent uncontrolled growth, which can lead to tumors.

What is the difference between haploid and diploid?

Haploid (N) has one set of chromosomes, while diploid (2N) has two sets.

What are homologous chromosomes?

Chromosomes of the same type that can pair during meiosis.

What is crossing over in meiosis?

The exchange of genetic material between non-sister chromatids during prophase I.

What occurs during metaphase I of meiosis?

Tetrads migrate to the middle of the cell.

What happens to homologous chromosomes during anaphase I?

Homologs separate and move to opposite poles of the cell.

What is the result of telophase I in meiosis?

The cell divides, resulting in two haploid daughter cells, each with one chromosome of each homologous pair.

What is the outcome of meiosis II?

The division results in four haploid daughter cells, each containing single chromosomes.

What are spermatocytes and oocytes?

They are immature gametes; spermatocytes develop into sperm, and oocytes develop into eggs.

Who is Gregor Mendel and what did he discover?

Mendel discovered the basic principles of inheritance through experiments on garden peas in the 1860s.

What is the chromosome theory of inheritance?

Proposed by Sutton and Boveri, it states that genes are located at specific positions on chromosomes.

What is blending inheritance?

The hypothesis that parental traits blend to produce intermediate traits in offspring.

What is a monohybrid cross?

A mating between parents with two different phenotypes for a single trait.

What is Mendel's principle of segregation?

Each parent contributes a single set of genes to their offspring, resulting in two copies of each gene.

What is a test cross?

A method to determine if an individual with a dominant phenotype is homozygous or heterozygous for that trait.

What does the law of independent assortment state?

Genes located on different chromosomes assort independently into gametes.

What is the significance of the F1 and F2 generations in Mendelian genetics?

The F1 generation is the first hybrid generation, while the F2 generation is produced by self-pollination of F1 plants.

What is polymorphism in genetics?

Variation in the genotype among individuals, leading to different phenotypes.

How do you determine the probability of independent events in genetics?

By multiplying the individual probabilities of each event.

What is the role of alleles in inheritance?

Alleles are different forms of a gene inherited from each parent, contributing to the organism's genotype.

What is the phenotype?

The observable expression of an organism's genotype.

What are polar bodies in oogenesis?

Small cells that are produced during oocyte division that typically do not develop into mature eggs.

What is the Sum Law in probability?

The probability that any of several mutually exclusive events will occur is found by adding the individual probabilities of those events.

What are multiple alleles?

When there are more than two alleles of a gene in a population.

What is codominance?

A genetic scenario where neither allele is dominant or recessive, and heterozygotes display the phenotype of both alleles.

What is incomplete dominance?

A genetic scenario where heterozygotes have an intermediate phenotype, such as pink flowers from a red and white flower cross.

What determines the genotype in mammals?

The presence or absence of the Y chromosome; XX is female and XY is male.

What is gonadal sex?

Controlled by the presence or absence of proteins produced by the SRY gene on the Y chromosome, leading to the development of testes or ovaries.

How is phenotype defined in terms of sex?

An individual's sex is determined by their internal and external genitalia, secondary sex characteristics, and behavior.

What is the difference between gender and sex?

Gender refers to a person's internal sense of their identity (male or female), while sex is based on biological characteristics.

What are the characteristics of X-linked traits?

Always use XX and XY notation; males are affected more frequently than females, and the trait is never passed from father to son.

What are the characteristics of autosomal recessive traits?

Males and females are equally likely to be affected; affected offspring often have unaffected parents who are carriers.

What are the characteristics of autosomal dominant traits?

Males and females are equally likely to be affected; affected offspring have at least one affected parent.

What are the characteristics of X-linked recessive traits?

Males are affected more frequently; affected sons are usually born to carrier mothers, and the trait often skips generations.

How can pedigrees be used in genetics?

Pedigrees are used to learn the mode of transmission for a given trait, indicating whether it is autosomal or sex-linked.

What is the expected outcome if both parents are heterozygous for an autosomal recessive trait?

About ¼ of the offspring will be affected.

What happens if one parent is heterozygous for an autosomal dominant trait?

About ½ of the offspring will be affected.

What is a common example of incomplete dominance in plants?

Crossing pure-line red flowers (RR) with pure-line white flowers (rr) results in heterozygous offspring with pink flowers (Rr).

What is familial hypercholesterolemia?

An example of incomplete dominance in humans where heterozygotes have an intermediate phenotype.

What is the significance of the TDF protein?

It is produced by the SRY gene on the Y chromosome and is crucial for determining gonadal sex.

What is the expected outcome for daughters of an affected male with an X-linked trait?

All daughters will be carriers if the mother is an unaffected non-carrier.

What does it mean if a trait skips generations?

It indicates that the trait is likely autosomal recessive or X-linked recessive, where unaffected parents can have affected offspring.

During the light reactions, as electrons pass through thesystem of electron carriers, they lose energy. What happensto this energy?

It is used to establish and maintain a proton gradient for the generation of ATP

Which of the following happens during the light reactions ofphotosynthesis?

ATP is made using light energy

What is the role of water in photosynthesis?

It donates electrons and hydrogens, it creates oxygen

What is the purpose of light reactions?

it converts light energy into chemical energy in the form of ATP and NADPH. These reactions also produce oxygen as a byproduct.

What is the purpose of the Calvin cycle?

It uses the ATP and NADPH produced during the light reactions to convert carbon dioxide into glucose

What processes do photosynthesis and cellular respiration share?

Chemiosmosis

Use the terms anabolic and endergonic to describe photosynthesis

-Anabolic: It builds complex molecules (glucose) from simpler ones (carbon dioxide and water).

-Endergonic: It requires an input of energy (from sunlight) to proceed.

Use the terms catabolic and exergonic to describe cellular respiration

-Catabolic: It breaks down complex molecules (glucose) into simpler ones (carbon dioxide and water).

-Exergonic: It releases energy (in the form of ATP) as it proceeds.

How are photosynthesis and cellular respiration products and reactants related?

The products of photosynthesis are the reactants for cellular respiration, and the products of cellular respiration are the reactants for photosynthesis

A cell undergoing mitosis in a small mammal contains eight chromosomes. How many chromosomes are there in the mammal's cell at the end of G2 phase?

8 chromosomes

Another name for a microtubule-organizing center (MTOC) in animal cells is _____?

Centrosome

Two joined copies of a replicated chromosome are called _____?

Sister chromatids

What is triploid? How many sets of chromosomes?

A triploid describes a cell or organism that has three sets of chromosomes

If humans were triploid, how many chromosomes would we have?

69 chromosomes

A horse has 64 chromosomes, a donkey 62. How many chromosomes in a mule?

63 chromosomes

Do you think a mule is fertile? Why or why not?

No, with the mule having a odd number of chromosomes it makes it impossible for the chromosomes to link up perfectly during meiosis

How many cells produced in mitosis?

2 cells

How many cells produced in meiosis?

4 cells

How many cell divisions in mitosis?

1

How many cell divisions in meiosis?

2

What is the process of mitosis used for?

Growth, repair, and asexual reproduction

What is the process of meiosis used for?

Sexual reproduction and genetic diversity

What is the number of chromosomes in daughter cells compared to parent cells in mitosis?

Same number (diploid)

What is the number of chromosomes in daughter cells compared to parent cells in meiosis?

1/2 the number (haploid)

Can a haploid cell go through meiosis? Why or why not?

No, only 1 set of chromosomes

A horse has 64 chromosomes. How many chromosomes does a horse gamete have? How many chromatids at the start of prophase I?

32 chromosomes, 128 chromatids

Why are gametes produced by meiosis not mitosis?

To maintain proper number of chromosomes in each generation

Why are gametes different from each other? What happens during meiosis that makes gametes genetically different?

Crossing over, random assortment of homologs

A hypothetical organism has 6 chromosomes in each of its somatic cells. Skin cells are continuously being rubbed off and replaced. How many chromosomes will be contained in each new skin cell that is replaced?

6 chromosomes

A hypothetical organism has 6 chromosomes in each of its somatic cells. This replacement occurs through the process of ________________?

Mitosis

A hypothetical organism has 6 chromosomes in each of its somatic cells. Each somatic cell of this organism has how many chromosomes?

6 chromosomes

A hypothetical organism has 6 chromosomes in each of its somatic cells. The diploid number (2N) for this organism is _______?

6

A hypothetical organism has 6 chromosomes in each of its somatic cells. This organism would have how many homologous pairs of chromosomes?

3

A hypothetical organism has 6 chromosomes in each of its somatic cells. The female of this organism has an ovary. The number of chromosomes in each of the cells that make up the ovary would be_______.

6

A hypothetical organism has 6 chromosomes in each of its somatic cells. The mature eggs of this female would contain how many chromosomes?

3

A hypothetical organism has 6 chromosomes in each of its somatic cells. The zygote divides many times to form all of the cells of the new" baby". This type of division is called ____________?

Mitosis