Genetics/Meiosis

Question 1

what happens before mitosis

Answer 1

Interphase- cell grows replicates its chromosomes and gerts ready for cell division

Question 2

what happens before meiosis occurs

Answer 2

Interphase- the DNA in each chromosome is replicated

Question 3

what is the purpose of meiosis

Answer 3

to create sex cells

Question 4

what is the purpose of mitosis

Answer 4

create more cells; growth repair

Question 5

what does meiosis produce

Answer 5

four haploid cells in which each chromosome has just one chromatid.

Question 6

what does mitosis produce

Answer 6

two daughter cells

Question 7

What are Homologous chromosomes?

Answer 7

Two chromosomes in a pair normally one inherited from the mother and one from the father

Question 8

What is the difference between a haploid cell and a diploid cell?

Answer 8

Diploid cells are two full sets of chromosomes while haploid cells are one full set of chromosomes.

Question 9

What is the difference between autosomes and sex chromosomes?

Answer 9

Autosomes- 1-22
Sex- 23, XY determines gender

Question 10

What identifies a human genetically as female? As male?

Answer 10

females inherit an X chromosome from the father for a XX genotype, while males inherit a Y chromosome from the father for a XY genotype (mothers only pass on X chromosomes)

Question 11

What is a Karyotype?

Answer 11

an individual’s complete set of chromosomes.

Question 12

What is nondisjunction?

Answer 12

When chromosomes don’t separate- its a mistake

Question 13

what is crossing over

Answer 13

the process by which genetic material is exchanged/transfered by homologous chromosomes during meiosis- prophase I

Question 14

How does crossing over occur

Answer 14

during meiosis when chromosomes of the same type are lined up

Question 15

what is independent assortment

Answer 15

the alleles of two (or more) different genes get sorted into gametes independently of one another

Question 16

How does independent assortment occur

Answer 16

when paired homologous are separated into daughter cells during meiosis.

Question 17

How does independent assortment occur contribute to genetic diversity?

Answer 17

because certain genes are not connected with one another. some traits that are inherited from the parents will not clump together for the new offspring.

Question 18

What is random fertilization

Answer 18

during sexual reproduction, the male gamete and female gamete that fuse to produce an offspring are selected randomly from the pool of male and female gametes.

Question 19

how does random fertilization lead to genetic variation

Answer 19

When a male gamete and a female gamete finally meet, each is the result of an immense number of genetic possibilities created during independent assortment and crossing over.

Question 20

what are the pedigree symbols for male and female

Answer 20

A male is represented by a square or the symbol ♂, a female by a circle or the symbol ♀.

Question 21

what are the differences between genotype and phenotype

Answer 21

The phenotype is an organism’s physical appearance, and the genotype is the genetic makeup.

Question 22

Genotype and Phenotype example

Answer 22

Genotype- Bb, Phenotype- brown fur

Question 23

differences between an allele and a gene?

Answer 23

Gene is defined as a section of DNA that encodes for a certain trait.
An allele is defined as a variant form of a gene

Question 24

differences between a Homozygous and Heterozygous?

Answer 24

Being homozygous for a particular gene means you inherited two identical versions. It’s the opposite of a heterozygous genotype, where the alleles are different.

Question 25

Homozygous and Heterozygous example

Answer 25

Homozygous- BB bb, Heterozygous- Bb

Question 26

Incomplete Dominance

Answer 26

a form of Gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype

Question 27

Codominance

Answer 27

means you see both of the traits such as having a cow with black spots means it has white and black genes,

Question 28

Multiple Alleles

Answer 28

three or more possible alleles for one individual trait.

Question 29

Sex Linkage

Answer 29

refers to characteristics (or traits) that are influenced by genes carried on the sex chromosomes.

Question 30

What makes a trait sex-linked?

Answer 30

Refers to characteristics (or traits) that are influenced by genes carried on the sex chromosomes. Sex-linked traits are determined by genes found on the X and Y chromosomes Sex linkage applies to genes that are located on the sex chromosome

Question 31

Are X linked recessive traits more common in men or women? Why?

Answer 31

X-linked recessive diseases most often occur in males. Males have only one X chromosome. A single recessive gene on that X chromosome will cause the disease

Question 32

What are ways of determining whether a trait is dominant or recessive in a pedigree

Answer 32

if a trait skips a generation in a pedigree, it is often an autosomal recessive trait

Question 33

What are ways of determining whether a trait is X-linked or autosome

Answer 33

Autosomal dominant traits pass from one parent onto their child X linked traits are passed through mutations (changes) in a gene on the X chromosome