Reproduction, Genetics, and Cellular Transport

Flashcards covering reproduction types, meiosis, Mendelian genetics, Hardy-Weinberg formulas, and cellular transport mechanisms based on the lecture notes.

What is asexual reproduction?

Reproduction involving one parent that creates genetically identical offspring (clones).

How does binary fission occur, and what example organism is provided in the text?

Binary fission occurs when an organism divides into two; an example is paramecium.

How does budding occur, and in what organism is it observed?

Budding occurs when a new organism grows off the parent; it is seen in hydra.

What occurs during fragmentation/regeneration in asexual reproduction?

Pieces of an organism can grow into new organisms.

What cell division process is used in asexual reproduction, and does it involve gametes?

Asexual reproduction uses mitosis and does not involve gametes or fertilization.

What are the advantages and disadvantages of asexual reproduction?

It is quick and efficient, but it offers low genetic diversity, which limits adaptability.

What is sexual reproduction?

Reproduction involving two parents that mix their genes to create unique offspring.

What mechanisms are involved in sexual reproduction?

It involves meiosis (creating gametes like sperm and eggs) and fertilization (union of egg and sperm).

How do asexual and sexual reproduction compare regarding parent count, offspring genetics, speed, and genetic diversity?

Asexual reproduction involves one parent, creates identical clones, is fast, and has low genetic diversity. Sexual reproduction involves two parents, creates unique combinations, is slower, and yields high genetic diversity.

How is DNA defined in the notes?

The genetic blueprint.

What is a chromosome?

A thread-like structure made of DNA.

What is the difference between diploid ($2n$) and haploid ($n$) cells?

Diploid ($2n$) cells contain two sets of chromosomes (like human body cells), whereas haploid ($n$) cells contain one set of chromosomes (like human gametes).

What is a gamete?

A haploid sex cell (sperm or egg).

What is the main purpose of meiosis and how does it affect chromosome count in humans?

The purpose is to produce four unique haploid gametes from one diploid cell, cutting the chromosome count in half (from $46$ to $23$ in humans).

What happens during Meiosis I versus Meiosis II?

In Meiosis I, homologous chromosomes pair and separate. In Meiosis II, sister chromatids split into individual gametes.

What occurs during fertilization?

Fertilization joins two haploid gametes to form a diploid zygote.

What are the four sources of genetic variation described in the transcript?

Crossing-Over (swapping sections of DNA), Independent Assortment (random sorting of chromosomes), Random Fertilization (any sperm fertilizing any egg), and Mutations (errors in DNA).

How do mitosis and meiosis differ in terms of cellular output and function?

Mitosis produces two identical diploid cells used for growth, repair, and asexual reproduction. Meiosis creates four non-identical haploid cells strictly for gamete formation in sexual reproduction.

What are the four common stages of cell division shared by both mitosis and meiosis?

Prophase, metaphase, anaphase, and telophase.

How does cytokinesis differ between animal cells and plant cells?

In animal cells, a furrow pinches apart to divide the cell, whereas in plant cells, a cell plate forms to separate the cells.

What is the Law of Segregation?

The principle that alleles (gene versions) separate during meiosis, ensuring each gamete receives only one allele.

What is the Law of Independent Assortment?

The principle that genes located on different chromosomes are inherited independently of each other.

What is the difference between dominant and recessive alleles?

Dominant alleles are expressed if present (e.g., $AA$ or $Aa$), while recessive alleles are only expressed if both alleles are recessive (e.g., $aa$).

What are the offspring results for a $BB \times bb$ monohybrid cross and a $Bb \times Bb$ monohybrid cross?

A $BB \times bb$ cross yields all $Bb$ (heterozygous) offspring. A $Bb \times Bb$ cross yields a $3$ dominant to $1$ recessive phenotype ratio.

What is incomplete dominance?

A non-Mendelian pattern where heterozygotes show a mix of both traits.

What is gene linkage?

The tendency of genes that are close together on a chromosome to be inherited together.

What is a pedigree?

A chart that shows how traits are passed through generations.

What phenotypic ratio is produced in a dihybrid cross of two heterozygous parents ($AaBb \times AaBb$)?

A $9:3:3:1$ phenotypic ratio.

What are the Hardy-Weinberg equations for allele frequencies and genotype frequencies?

Allele Frequencies equation: $p + q = 1$ (where $p$ and $q$ are allele frequencies). Genotype Frequencies equation: $p^2 + 2pq + q^2 = 1$.

What is the structure of the cell membrane according to the notes?

A phospholipid bilayer composed of hydrophilic heads and hydrophobic tails, along with membrane proteins that assist in moving larger or charged substances across.

What is passive transport and what are its three types?

Movement from high to low concentration without energy use ($\text{ATP}$). Its types are Simple Diffusion, Facilitated Diffusion, and Osmosis.

How do isotonic, hypotonic, and hypertonic solutions affect cells?

An isotonic solution has equal solute concentration. A hypotonic solution has a lower outside concentration, causing cells to swell. A hypertonic solution has a higher outside concentration, causing cells to shrink.

What is active transport and what are two specific types mentioned?

Movement from low to high concentration requiring energy ($\text{ATP}$). Two types are Endocytosis (bringing in large materials) and Exocytosis (releasing materials through vesicles).