Download 4-3 Challenge Practice Questions

The Cell and Inheritance
Section 4-3
What are chromosomes?
What are chromosomes?
• Chromosomes are rod shaped pieces of
genetic material.
Where do you find chromosomes?
Where do you find chromosomes?
• Chromosomes are found in the nucleus of
a cell.
When are chromosomes visible?
When do chromosomes appear?
• Chromosomes are only visible during cell
division.
chromosomes
What is the chromosome theory
of heredity?
What is the chromosome theory
of heredity?
• The chromosome theory of heredity states
that genes are passed from parent to
offspring on chromosomes.
Sutton
Why are chromosomes
found in pairs?
Why are chromosomes
found in pairs?
• During fertilization, an organism receives
two set of chromosomes, one from the
father and the other from the mother.
Why do most chromosomes have
an “X” shape?
Why do most chromosomes have
an “X” shape?
• Chromosomes only appear
after DNA replication.
• One side of the “X” is the
original DNA and the
opposite side is an
identical copy of the DNA.
• The two copies of DNA are
connected by the
centromere.
True or False?
• Chromosomes carry genes from parents
to offspring.
True or False?
• Chromosomes carry genes from parents
to offspring.
• True – This is the chromosome theory
of inheritance.
How many chromosomes do
human body cells contain?
How many chromosomes do
human body cells contain?
• 46
or
• 23 pairs
How many chromosomes do
human sex cells contain?
How many chromosomes do
human sex cells contain?
• 23
How are genes lined up on a pair of
chromosomes?
How are genes lined up on a pair of
chromosomes?
• Like beads on a string
• In the same order on both pairs
During which process do chromosome pairs
in a cell separate and form into sex cells?
During which process do chromosome pairs
in a cell separate and form into sex cells?
• meiosis
True or False?
• During meiosis, the two alleles for each
gene stay together.
True or False?
• During meiosis, the two alleles for each
gene stay together.
• False -- the alleles separate to make
different sex cells
True or False?
• A Punnett square is a way of showing the
events that occur during meiosis.
True or False?
• A Punnett square is a way of showing the
events that occur during meiosis.
• True
True or False?
• Grasshopper sex cells have half the
number of chromosomes as its body cells.
True or False?
• Grasshopper sex cells have half the
number of chromosomes as its body cells.
• True
– Body cell
= 24 chromosomes
– Egg cell
= 12
– Sperm cell = 12
True or False?
• There are twice as many chromosomes in
sex cells than in body cells.
True or False?
• There are twice as many chromosomes in
sex cells than in body cells.
• False – There are half as many chromosomes in the sex cell as the body
cell
True or False?
• A sperm cell has half as many
chromosomes as a body cell.
True or False?
• A sperm cell has half as many
chromosomes as a body cell.
• True
True or False?
• A fertilized egg has the same number of
chromosomes as a body cell of its parents.
True or False?
• A fertilized egg has the same number of
chromosomes as a body cell of its parents.
• True – a fertilized egg has a complete set
of chromosomes from both parents.
23 + 23 = 46
Define meiosis.
Define meiosis.
• Meiosis is the process by which
– a body cell reduces the number of its
chromosomes
– by half
– in order to make a sex cell.
How many daughter cells are created
from a parent cell during meiosis?
How many daughter cells are created
from a parent cell during meiosis?
• 4
What structures carry genes from
the parents to its offspring?
What structures carry genes from
the parents to its offspring?
• chromosomes
Fill In the Blank
The chromosomes in a pair may each have
different __________ for each gene.
Fill In the Blank
The chromosomes in a pair may each have
alleles
different __________
for each gene.
allele – two different forms
of the same gene