Unit 1 Exam Review: Genetics

Question 1

What happens during mitosis?

Answer 1

Mitosis is the process by which a single cell divides to create two identical daughter cells

Question 2

What happens during meiosis?

Answer 2

Meiosis is a type of cell division that occurs in sexually reproducing organisms, resulting in the formation of gametes (sperm and egg cells)

Question 3

What are the stages of mitosis? What happens in each stage?

Answer 3

Prophase - membrane of the nucleus disappears, chromosomes are formed, centrioles start producing spindle fibres.

Metaphase - spindle fibres attach to chromosomes, spindle fibres pull to line up chromosomes near the equator of the cell.

Anaphase - spindle fibres pull chromosomes apart, one chromatid moves towards each side.

Telophase - chromatids reach the poles of the splitting cell, new nebular membranes form around the chromatids, the cell membrane starts to separate.

Question 4

What is cytokinesis?

Answer 4

It’s the final step in cell division, where the cell membrane pinches inward in a cell to create two distinct daughter cells.

Question 5

What is the process of genetic variation in meiosis called?

Answer 5

“Crossing over”

Question 6

How does crossing over work in meiosis?

Answer 6

Occurs between prophase 1 and metaphase 1.
Chromosomes exchange genetic material
Creates more genetic variation between parent and daughter cells

Question 7

What are the 5 genetic disorders?

Answer 7

1. Down syndrome
2. Edward’s syndrome
3. Patau syndrome
4. Klinefelter syndrome
5. Turner’s syndrome

Question 8

Down syndrome: what chromosome is affected? How does it occur? Side affects?

Answer 8

• Chromosome 21 has an extra chromosome
• Can result from non disjunction in a sperm or egg cell
• Heart defects
• Round face, large forehead
• Development and intellectual challenges

Question 9

Edward’s syndrome: what chromosome is affected? How does it occur? Side affects?

Answer 9

• chromosome 18 has an extra chromosome
• non disjunction in a sperm or egg cell
• many organ system defects
• very low survival rate (most die before birth)

Question 10

Patau syndrome: what chromosomes are affected? How does it occur? Side affects?

Answer 10

• chromosome 13 has an extra chromosome
• caused by non disjunction in the sperm or egg cell
• brain, kidney, and heart defects
• serious development problems
• children rarely live more than a few months

Question 11

Klinefelter syndrome: what chromosomes are affected? What occurs? Side affects?

Answer 11

• has 2 X chromosomes and 1 Y chromosome
• appear male at first but develop high levels of female hormones

Question 12

Turner’s syndrome: what chromosomes are affected? How does it occur? Side affects?

Answer 12

• only 1 X chromosome and 0 Y chromosomes
• results from non disjunction in a sperm or egg cell
• increased weight, low hairline, short stature

Question 13

Single Trait Inheritance Practice Questions

A plant that is homozygous for purple flowers is crossed with a plant that has white flowers. If purple is dominant over white, determine the genotypes and phenotypes of the F1 generation.

Answer 13

P1 = PP x pp​​genotype – all Pp​phenotype - all purple

Question 14

Monohybrid Cross Practice (no answer sheet)

Answer 14

In flowers red petals are dominant to white petals. Use a Punnett square to predict the possible phenotypes and genotypes of the F1 generation from a cross between a plant pure-breeding for red petals and a plant pure-breeding for white petals. Use the letter R to represent this trait.