2.6.4- Diversity In Animal Cells Flashcards
What are epithelial cells?
Cells that constitute lining tissue.
What is an erythrocyte?
A red blood cell.
What is a neutrophil?
A type of red blood cell that is phagocytic- can invest microbes and small particles.
Explain what a stem cell is.
An unspecialised cell able to express all of its genes and divide by mitosis.
Single called organisms are small and therefore have a large what?
Surface area to volume ratio.
Give two reasons for the need of a large SA:V ratio.
It means lots of oxygen can quickly and efficiently diffuse into the cell and waste products can diffuse out of the membrane efficiently.
Why do larger organisms need specialised cells?
Most of their cells aren’t in contact directly with the exterior environment, therefore they need specialised cells to carry out a particular function.
How does a multicellular embryonic organism start life?
As a single undifferentiated cell called a zygote.
Explain how a zygote forms.
The suite is made when an ovum is fertilised by a sperm and the two haploid nucleus’ fuse (= diploid nucleus). The zygote is unspecialised and all of the genes in its genome an be expressed and t an divide by mitosis.
What is a genome?
The genetic material within an individual.
What can happen to genes during differentiation?
Some can be swifter off and some expressed more.
List three reasons as to why certain genes may be switched off or expressed more during differentiation.
The proportions of the different organelles differs from those of other cells, the shape of the cell changes and some of the contents of the cell changes.
From where do erythrocytes and neutrophils derive?
The stem cells within bone marrow.
List the five types of specialised animal cells.
Neutrophil Erythrocyte Spermatozoa Ciliated epithelia Squamous epithelia
What is the function of erythrocytes?
They carry oxygen from the lungs to respiring cells.