Unit 17 Flashcards
what are chromosomes
they are made of DNA which contains genetic information in the form of genes
what is a gene
a length of DNA that codes for a protein
WHat is an allele
the alternative form of a gene
what are the sex chromosomes
the pair of chromosomes that determine gender
what is the female sexy chromosome
X and X
what is the male sex chromosome
X and Y
what chromosome do female eggs carry
X chromosomes
what chromosomes do sperm cells carry
X or Y
they determine the gender of the baby
what is the smallest to largest(DNA,Chromosomes,Genes)
DNA, Genes,Chromosomes
how are specific proteins created
the different sequences of bases in a gene determines the sequence of amino acids to give protein molecules different shapes
How does DNA control cell function
controls the production of proteins such as enzymes,membrane carriers and receptors for neurotransmitters
how is a protein made
the gene coding for the protein remains in the nucleus
mRNA is a copy of a gene
mRNA molecules are made in the nucleus and move to the cytoplams
how is a protein made
the gene coding for the protein remains in the nucleus
mRNA is a copy of a gene
mRNA molecules are made in the nucleus and move to the cytoplasm
mRNA passes through ribosomes
the ribosome assembles amino acids into the protein molecules
specific sequence of amino acids is determined by the sequence of bases
how do most body cells in an organism contain the same genes but have different functions
genes in the particular cells are not expressed because the cell only makes the specific proteins required
what are haploid cells
cells with a nucleus containing a singular set of chromosomes
what are diploid cells
nucleus contains 2 sets of chromosomes
what is mitosis
nuclear division giving rise to genetically identical cells
what is mitosis used for
used in growth, repair of damaged tissus, replacement of cells and asexual reproduction
how does mitosis create genetically identical cells
the exact replication of chromosomes occurs before mitosis
what happens during mitosis
the copies of chromosomes separate which maintains the chromosome number in each daughter cell
what are stem cells
unspecialised cells that divide by mitosis to produce daughter cells that can then be specialised for specific functions
what is meiois
cell division where 4 genetically unique cells are created
what is meiosis used for
the production of games
what is inhertitance
the transmission of genetic information from generation to generation
what is the genotype
the genetic makeup of an organism in terms of the alleles present
what is the phenotype
the observable features of an organism
homozygous
2 identical alleles of a particular genes
what happens when 2 homozygous individuals breed
pure breeding
heterozygous
two different alleles of a particular gene
can heterozygous individuals be pure bred
no
dominant allele
an allele that is expressed if its present in the genotype
recessive allele
only expressed when there is no dominant allele of the gene present
what is codominance
a situation where both alleles contribute to the phenotype
what is a sex linked characteristic
a feature where the gene responsible is located on a sex chromosome
the characteristic is more present in one gender
why is red green color blindness more common in males
the gene is located on the X chromosome
more common in males since they only require one faulty X chromosome while females require 2 faulty chromosomes
