Biology Unit 4 Genetics (Flashcards)

What are eukaryotic chromosomes made of?
They are made of DNA and proteins
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What are plasmids?
Prokaryotic DNA in the form of small loops
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What do prokaryotic chromosomes not contain?
Protein
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Define gene
a heritable factor that controls a specific characteristic, consists of a length of DNA and occupies a position on a chromosome known as a locus
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Define allele
a specific form of a gene, occupies the same locus as other alleles of that gene
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Define genome
total genetic material of an organelle, cell or organism
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Define gene pool
total of the genes carried by individual members of a population
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Define gene mutation
permanent change in the sequence of base pairs in the DNA that makes up a gene
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Define meiosis
a reduction division of a diploid nucleus to form haploid nuclei
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Define homologous chromosomes
two chromosomes, one from each parent that look the same. They show the same binding pattern in a karotype, carry the same genes but not always the same alleles. They pair and split up in meiosis
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What happens in karotyping?
chromosomes arrange in pairs according to their size and structure.
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Give an example of a gene with multiple alleles
Blood groups -IA, IB, and i.
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Define genotype
alleles of an organism
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Define phenotype
all the characteristics of an organism. This is written as a word
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Define dominant allele
ne which has the same effect on the phenotype whether it is present in the homozygous or heterozygous state
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Define recessive allele
one which only has an effect on the phenotype when present in the homozygous state
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Define co-dominant alleles
pair of alleles that both affect the phenotype when presentin a heterozygote
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Define locus
particular position on homologous chromosomes of a gene
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Define homozygous
having 2 identical alleles of a gene
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Define heterozygous
having 2 different alleles of a gene
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Define carrier
an individual that has a recessive allele of a gene that does not have an effect on the phenotype
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Define test cross
testing a suspected heterozygote by crossing with a known homozygous recessive.
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Some genes are present on the __ chromosome but absent on the __ chromosome
Present on the X chromosome and absent on the Y chromosome
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Which is smaller X or Y chromosome?
Y is much smaller.
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Give an example of genes that are located only on the X-chromosome
Hemophilia and colour blindess
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What are genes for hemophilia and colour blindness sometimes referred as?
"X-linked"
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Are conditions that are "x-linked" more common on males or females?
Males
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Define Sex linkage
conditions like colour blindess and hemophilia are more common in men than in women and are sex-linked
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A human female can be _______ or ______ with respect to sex-linked genes
She can be homozygous or heterozygous
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Why is it possible for a female to heterozygous for a sex-linked gene
because she has 2 X chromosomes whereas men only have one.
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State Mendel's first law
Law of segregation - "parental factors (genes) are in pairs and split so that one factor is present in each gamete"
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State Mendel's second law
Principle of independent assortment - "any of one pair of characteristics may combine with either one of another pair"
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Why is possible for genes to be transferred between species?
The amino-acid sequence of the polypeptides translated from them is unchanged because the genetic code is universal
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Give an example of when the universal genetic code is useful in humans?
It is possible to introduce a human gene from making insulin into a bacterium
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Define clone
group of genetically identical organisms/cells derived from a single parent cell
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Other cards in this set

Card 2

Front

Prokaryotic DNA in the form of small loops

Back

What are plasmids?

Card 3

Front

Protein

Back

Preview of the back of card 3

Card 4

Front

a heritable factor that controls a specific characteristic, consists of a length of DNA and occupies a position on a chromosome known as a locus

Back

Preview of the back of card 4

Card 5

Front

a specific form of a gene, occupies the same locus as other alleles of that gene

Back

Preview of the back of card 5
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