Genetics Flashcards

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0
Q

What is a ploidy number?

A

Number of copies of each chromosome
Ex: humans= two copies of each chromosome from mom/dad
2n=46

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1
Q

What is a haploid number?

A

One copy of each chromosome (distinct)

Ex: gamete n=23

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2
Q

What is a chromosome?

A

Thread-like structure of nucleotides

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3
Q

What is a chromatid?

A

Each of the two thread like strands in which a cell divides into

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4
Q

What is a sister chromatid?

A

Two identical copies of a single chromosome

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5
Q

What is a nonsister chromatid?

A

Two chromatids of a homologous pair

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6
Q

What is a homologous pair?

A

Same chromosome from mom/dad

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7
Q

What is a tetrad?

A

Homologous pairs when lined up at the metaphase plate

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8
Q

What is an allele?

A

Different forms of a gene

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9
Q

What is a locus?

A

Where a gene is located on a chromosome

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10
Q

What is a centrosome?

A

Pair of centrioles

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11
Q

What is a centriole?

A

Triplet micro tubule structure from which the mitotic spindle is formed

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12
Q

What is independent assortment?

A

“Law of segregation”

Allele pairs seperate independently during the formation of gametes (meiosis 1/ metaphase 1)

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13
Q

What is Mendel’s Model?

A
  1. Multiple alleles for one phenotype
  2. For each character, an individual inherit two alleles; one from each parent
  3. If two alleles at the same locus differ, the dominant allele will determine appearance
  4. The law of segregation; the two alleles for a character segregate during gamete production and hence end up in different gametes
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14
Q

What did Mendel discover?

A

Some traits are dominant, some are recessive

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15
Q

What is genetics?

A

Scientific study of heredity

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16
Q

What is heredity?

A

Transmission of traits from one generation to another

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17
Q

What is a character?

A

Heritable features that vary among individuals

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18
Q

What is a trait?

A

(Phenotype) variant for the character

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19
Q

What is a model organism?

A

An organism that is widely used because it is easy to maintain in a lab setting

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20
Q

What is true breeding?

A

An organism that will always give certain traits to their offspring (phenotypic trait)

21
Q

What is hybridization?

A

Cross between two true breeding varieties with different phenotype a of the same character

22
Q

What are two other theories of heredities that failed?

A

Blended: black + white = grey
Acquired: modified traits in parents are passed to offspring

23
Q

What is incomplete dominance?

A

White + red = pink

24
Q

What is co dominance?

A

Red + white = red & white

25
Q

What is multiple allelism?

A

The existence of more than two alleles of the same gene

26
Q

What is polymorphism?

A

The presence of more then two phenotypes for a particular trait

27
Q

What is epistasis?

A

When the allele of one gene masks the affect of an allele of another gene

28
Q

What is aneuploidy?

A

Zygote has abnormal number of chromosomes

Ex: trisomy 21 (n+1)

29
Q

What does monosomic mean?

A

Missing a chromosome (2n-1)

30
Q

What does trisomic mean?

A

Triplicate chromosome (2n+1)

31
Q

What are the two phases of the cell cycle?

A

Interphase

Mitotic phase

32
Q

What are the three phases of interphase?

A

G1- sufficient nutrients
S- DNA synthesis
G2- replicated chromosomes

33
Q

What is mitosis?

A

Separation of genetic material

34
Q

What is cytokinesis?

A

Separation of cytoplasm

35
Q

What are the five phases of mitosis?

A
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
36
Q

Meiosis vs mitosis

A

Meiosis. Mitosis

Haploid. Diploid
Sex cells. Non sex cells
Make gametes. Make identical
Genetic variation Cells

37
Q

What are the cell cycle check points?

A

G1: sufficient nutrients
G2: all chromosome to spindles
M: all chromosomes attached to spindles

38
Q

What is a karyotype?

A

Number of distinct chromosomes present

39
Q

Meiosis 1 vs meiosis 2

A

Meiosis 1. Meiosis 2
Split up homo. Pair. Split up sister
2n. Chromatids
n

40
Q

What is crossing over?

A

Exchange of genetic material between homologous pairs (meiosis 1/ prophase 1)

41
Q

Independent assortment vs crossing over?

A

Independent Crossing over
Mixing/swapping Exchange of
places w/ chromes. Genetic material

42
Q

What was Mendel?

A

An Austrian monk who discovered the basics of genetics using peas

43
Q

What did Mendel’s experiments discover?

A

Some traits are dominant, some are recessive

44
Q

Sex chromosomes vs autosomal chromosomes

A

XX/XY. All other 22 Chrome
Determine Not involved in sex
If you’re Determining
A boy or a girl

45
Q

How does the environment influence phenotype?

A

(Nature vs nurture)
Less wind= taller tree
More nutrients= stronger organism

46
Q

Morgan 1907

A

Mendel took us so far, Morgan bring it up to a new level using fruit flies instead of peas (genotype & phenotype)

47
Q

X linked chromosomes- why do fathers pass x linked genes to daughters, not to sons?

A

When the XY split up 50% are X and 50% are Y. Two X’s make a daughter therefore they only pass X linked genes to daughters

48
Q

What is non disjunction?

A

Failure of separation of homologous pairs or sister chromatids either in meiosis 1 or meiosis 2
(Ana1). (Ana2)

49
Q

What are four ways chromosome structure can be altered?

A

Deletion
Duplication
Inversion
Reciprocal translocation