8- Mitosis and the Cell Cycle Flashcards
What is gene expression?
the process by which DNA directs protein synthesis to determine our traits
Why do living organisms need cell division? (3)
- Reproduction: creating a new organism (offspring)
- Growth and Development: Get bigger and mature into an adult
- Replace: old and damaged cells to maintain healthy tissues
What is binary fission?
Cell division resulting in 2 organisms
What form of reproduction is binary fission?
asexual
How do single celled eukaryotes go through binary fission?
mitosis
How does binary fission by prokaryotes function?
- The single loop of DNA is replicated from a starting point (origin) in both directions moving towards opposite ends of the cell
- Cell elongates during DNA replication
- Plasma membrane pinches in the middle to separate the 2 daughter cells
What is the purpose of mitosis?
responsible for growth, development and replacement of old and damaged cells in multicellular
What is the purpose of meiosis?
responsible for creating gametes (sperm and eggs) for sexual reproduction
How are chromosomes and chromatin packaged?
- Chromosomes: DNA during cell division –> chromatin tightly coiled around proteins
- Chromatin: DNA when cell is not dividing –> long thin threads
What are the 2 basic cell types based on the number of chromosomes they contain in the human body?
1) Somatic cells (body cells)
2) Gametes (sex cells; eggs and sperm)
What are somatic cells? How many chromosomes do they have?
- All of the cells that make up the tissues of our bodies
- Have 46 chromosomes (2 two set of 23 unique chromosomes, one set from each parent)
What are gametes cells? How many chromosomes do they have?
- Specialized reproductive cells, eggs and sperm
- Have only 23 chromosomes
What is a karyotype? How are the chromosomes arranged?
an organized profile of an organism’s chromosomes where they are arranged in pairs from largest to smallest in size
What is a karyotype? How are the chromosomes arranged?
an organized profile of an organism’s chromosomes where they are arranged in pairs from largest to smallest in size
What are autosomal chromosomes? How many pair do humans have?
all chromosomes that are not related to sex determination are autosomal chromosomes
- humans have 22 pairs
What are sex chromosomes and have do they differentiate between male and female in humans?
- chromosomes involved in sex determination
- In humans, males have 2 different sex chromosomes (XY) and females have 2 same sex chromosome (XX)
What is karyotyping used for?
diagnose genetic disorders
What is a zygote?
the new cell formed after one sperm cell enters the egg cell and their nuclei fuse together forming one nucleus containing both sets of chromosomes
How does a zygote grow?
grows by increasing its number of cells through repeated cell divisions
How is the original genetic information of zygotes copied?
it is copied exactly before each cell division, ensuring that all new cells have a complete copy of all the chromosomes
What is mitosis?
Cell division creating 2 daughter cells with identical copies of the original components
Why do certain somatic cells undergo mitosis?
to regenerate damaged or old tissues others when we are growing and developing
What type of cell division will most cells in our body undergo?
most cells will never undergo a mitotic cell division
What type of certain specialized cells undergo mitosis repeatedly?
stem cells