Lecture 10 - Meiosis, And The Laws Of Independent Assortment Amd Segregation

Question 1

What is meiosis?

Answer 1

Nuclear division that halves the chromosome number forming haploid gametes

Meiosis involves two rounds of division: Meiosis I and Meiosis II.

Question 2

In which phase does meiosis occur?

Answer 2

S phase

This phase involves the replication of DNA.

Question 3

What are the two main stages of meiosis?

Answer 3

Meiosis I and Meiosis II

Meiosis I is a reductive division, while Meiosis II separates sister chromatids.

Question 4

What happens during Prophase I of meiosis?

Answer 4

Chromosomes condense, homologues pair, and crossing over occurs

The stages of Prophase I include Leptotene, Zygotene, Pachytene, Diplotene, and Diakinesis.

Question 5

What is independent assortment?

Answer 5

The random orientation of homologous pairs at the equator during Metaphase I

This process contributes to genetic diversity.

Question 6

What occurs during Anaphase I?

Answer 6

Chromosomes with 2 chromatids move to separate poles

This movement is due to the contraction of spindle fibers.

Question 7

What is the result of Telophase I?

Answer 7

2 new daughter cells that are haploid, each containing 1 of each chromosome

Each daughter cell consists of 2 chromatids connected at the centromere.

Question 8

What happens during Metaphase II?

Answer 8

Individual chromosomes line up at the metaphase plate

This stage prepares for the separation of sister chromatids.

Question 9

What is the outcome of Telophase II?

Answer 9

Each of the 4 haploid daughter cells contains one chromosome of each type

This results in a total of four haploid cells.

Question 10

What is the particulate theory of inheritance?

Answer 10

Characters are distinct and have genes that are particulate in nature

This theory was proposed by Mendel.

Question 11

How many genes does each adult have for each character?

Answer 11

2 genes

These genes can have different versions called alleles.

Question 12

What happens to genes during gamete formation?

Answer 12

1 gene from each pair segregates equally into gametes

This process is essential for genetic variation.

Question 13

What is the significance of fertilization in genetics?

Answer 13

Fusion of gametes restores the pair and is random

This contributes to genetic diversity in offspring.

Question 14

What is F1 in genetic terms?

Answer 14

First filial generation after a cross

This is followed by F2, F3, etc.

Question 15

What is a monohybrid cross?

Answer 15

A genetic cross involving a single trait

Mendel’s experiments with peas are a classic example.

Question 16

What does the dominant genotype phenotype express?

Answer 16

The dominant phenotype is expressed if present; if not, the recessive phenotype is present

This reflects Mendel’s laws of inheritance.

Question 17

Fill in the blank: Offspring genotype is the combination of specific _______.

Answer 17

alleles

The genotype determines the phenotype expressed in the offspring.

Question 18

What law do monohybrid crosses demonstrate?

Answer 18

Mendels law of segregation: how to 2 alleles separate and reunite at random with one from each parent

Question 19

What law do dihybrid crosses demonstrate?

Answer 19

Independent Assortment: genes assort independently during gamete formation