Bio Lab Test 2

What are the stages of mitosis?

Prophase → Metaphase → Anaphase → Telophase

What separates in mitosis?

Sister chromatids.

What separates in meiosis I?

Homologous chromosomes.

What is nondisjunction?

Failure of chromosomes to separate properly.

What can a karyotype show?

Chromosome number, sex, abnormalities (e.g., trisomy 21).

How do cancer cells differ from normal cells?

Uncontrolled division, abnormal shape, large nuclei.

Who was Henrietta Lacks?

Patient whose cancer cells (HeLa cells) were used in research without consent.

What is the phenotypic ratio of a monohybrid cross (Aa × Aa)?

3:1

What is the phenotypic ratio of a dihybrid cross?

9:3:3:1

What is incomplete dominance?

Heterozygote shows intermediate phenotype.

What is codominance?

Both alleles are fully expressed.

What are ABO blood alleles?

IA, IB (codominant), i (recessive)

What is the null hypothesis?

No significant difference between observed and expected results.

Degrees of freedom for coin flip?

1

When is a result significant?

When χ² > critical value (e.g., 3.84 at df=1, p=0.05)

What does detergent do in DNA extraction?

Breaks cell and nuclear membranes.

What does salt do?

Helps DNA clump together.

What does cold alcohol do?

Precipitates DNA so it becomes visible.

What is PCR?

Amplifies DNA using a thermocycler.

What is gel electrophoresis?

Separates DNA fragments by size.

Chloroplast Structure

What is the function of the chloroplast?

Site of photosynthesis; converts light energy into chemical energy (glucose).

What wavelengths correspond to blue, green, and red light?

• Blue: ~450 nm

• Green: ~550 nm

• Red: ~650–700 nm

Why do plants appear green?

Chlorophyll reflects green light and absorbs red/blue.

What happens to a plant kept in the dark?

It stops producing glucose and will use stored starch.

What does iodine test for in leaves?

Starch (turns blue-black if present).

What does paper chromatography separate?

Pigments (chlorophyll a, b, carotenoids, xanthophylls).

How are chloroplasts linked to cyanobacteria?

Endosymbiotic theory—chloroplasts evolved from photosynthetic bacteria.

Which beans respire more: dry or dampened?

Dampened (they are metabolically active).

What gas is produced during respiration?

Carbon dioxide (CO₂).

What is a respirometer used for?

Measuring respiration rate via gas exchange.

What is fermentation?

Anaerobic breakdown of glucose producing small amounts of ATP.

What is the function of mitochondria?

ATP production via cellular respiration.Mitochondria are known as the powerhouse of the cell, responsible for generating ATP through the processes of oxidative phosphorylation and the Krebs cycle.

What types of life have a Mitochondria?

almost all eukaryotic organisms—complex life forms including animals, plants, fungi, and many protists

Structure of the mitochondria?

Prophase I (Meiosis)

Synapsis and crossing-over occur

Metaphase I (Meiosis)

Homologous chromosomes align at the cell's equatorial plate.

Anaphase I

Homologues Separate

Telophase I

Sister Chromatids separate

Spermatogenesis: Meiosis I

Primary Spermatocyte 2n cell undergoes meiosis to produce two secondary spermatocytes which are haploid (n).

Spermatogenesis: Meiosis II

is a process that occurs in the testes, where a diploid primary spermatocyte divides to form two haploid secondary spermatocytes, each containing one set of chromosomes.

Spermatogenesis: Metamorphosis and Maturation

This phase involves the transformation of spermatids into mature sperm cells (spermatozoa), characterized by the development of a flagellum and the condensation of the nucleus.

OOGENESIS: Meiosis I

The process where a primary oocyte (2n) undergoes meiosis to produce one secondary oocyte and a polar body, with the secondary oocyte being haploid (n).

OOGENESIS: Meiosis II

is the stage in oogenesis where the secondary oocyte completes meiosis, resulting in one mature ovum and another polar body, both haploid (n), completing the process of oocyte development.

OOGENESIS: Fertilization

is the process where a sperm cell fuses with a mature ovum, resulting in the formation of a diploid zygote, and initiating the development of a new organism.

Thermocycler

A device used in PCR (polymerase chain reaction) to rapidly heat and cool samples, allowing for the amplification of DNA.

Gel Electrophoresis

is a laboratory technique used to separate nucleic acids or proteins based on their size and charge, allowing for analysis and identification.