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Flashcards in Chapter 6 Deck (35)
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1
Q

Genetics

A

the science that describes the inheritance of traits from one generation to another

2
Q

Gene

A

a length of DNA coding for a particular gene product, is the fundamental unit of inheritance

3
Q

Alleles

A

different versions of a gene

4
Q

Genotype

A

is the DNA sequence of the alleles a person carries

5
Q

Heterozygote

A

a person carrying two different alleles at a given locus

6
Q

Homozygote

A

individual carrying two identical alleles

7
Q

Phenotype

A

is the physical expression of the genotype

8
Q

Incomplete dominance

A

phenotype of a Heterozygote is a blended mix of both alleles

9
Q

Codominance

A

two alleles are both expressed but not blended

10
Q

Meiosis

A

reduces the number of copies of each chromosome from two to one

11
Q

Difference between mitosis and meiosis

A

replication of the genome is followed by one round of cell division in mitosis and two rounds of cell division in meiosis, meiosis I and meiosis II

In meiosis, recombination occurs between homologous chromosomes

12
Q

Bivalent or tetrad

A

Homologous chromosomes that align themselves very precisely with each other in synapsis, with the two copies of each gene on two different chromosomes

13
Q

Nondisjunction

A

failure of chromosomes to separate correctly during meiosis

14
Q

Gametes resulting in nondisjunction

A

will have two copies of a given chromosome

15
Q

Law of segregation

A

states that the two alleles of an individual are separated and passed on to the next generation singly

16
Q

Law on independent assortment

A

states that the alleles of one gene will separate into gametes independently of alleles for another gene

17
Q

Pure-breeding strain

A

A group of identical individuals that always produce offspring of the same phenotype when intercrossed

18
Q

Rule of multiplication

A

the probability of both of the two independent events happening can be found by multiplying the odds of either event alone

A*B = AB

19
Q

Rule of addition

A

calculate the chances of either of two events happening. (A+B) - (AB) = A or B

20
Q

Linkage

A

failure of genes to display independent assortment

when genes are located close to each other on the same chromosome, they will display linkage and may not assort independently

21
Q

Recombination

A

produces new combinations of alleles not found in the parent and also allows genes located on the same chromosome to assort independently

22
Q

Frequency of recombination between two genes on a chromosome is proportional

A

to the physical distance between the genes along the linear length of the DNA molecule

The farther two genes are away from each other, the greater the odds that recombination will occur between them

23
Q

RF= Recombination frequency

A

(number of recombinants)/(total number of offspring)

24
Q

Autosomal dominant

A

in which case a single copy of the allele will confer the trait or disease phenotype

Does not skip generations male and females affected equally, affected parent passes trait to either all or half of the offspring

25
Q

Autosomal recessive

A

in which case two copies of the allele are require for the affected phenotype

can skip a generation, number of affected males is usually equal to the number of affected females

26
Q

Y-linked

A

Affects males only; females never have the trait, affected father has all affected sons, unaffected father cannot have an affected son

27
Q

X-Linke recessive

A

Can skip generations, tend to affect males more than females, unaffected females can have affected sons, affected female has all affected sons, but can have both affected and unaffected daughters

28
Q

Pedigree

A

researchers can determine the pattern of inheritance of a gene, whether it is linked to other genes and whether an individual is likely to pass on a trait to their offspring

29
Q

Population Genetics

A

describes the inheritance of traits in populations over time

30
Q

Population

A

consists of members of a species that mate and reproduce with each other

31
Q

Gene pool

A

sum total of all genetic information in a population

32
Q

Hardy-Weinberg Law

A

States that the frequencies of alleles in the gene pool of a population will not change over time, provided that

There is no mutation, migration, natural selection, random mailing, and the population its sufficiently large to prevent random drift in allele frequencies

33
Q

alelle frequency equation

A

p+q=1

34
Q

genotype frequency equation

A

p^+pq+q^=1

35
Q

Hardy-Weinberg Equillibrium

A

After one generation allele frequencies no longer change