Answer:
Following Statements are true.
1. Cells receive molecular signals that communicate their position in relation to other cells.
3. Differential gene expression affects the developmental process in animals.
4. Positional information controls pattern formation.
6. Homeotic genes code for transcription factors that control the development of segment-specific body parts.
Explanation:
The formation of an eukaryotic organisms's spatial organization which includes organ formation and tissue arrangement is called as Pattern formation.
Molecular signals are received by cell. This phenomenon collectively refereed as positional information. Through this phenomenon cells are informed about their locomotion with respect to body axes and other cells. Regulation of pattern formation is controlled by Positional information.
When body axes is established a gene called homeotic gene start working as regulatory genes. This gene identify specific body segment in an organism which results in the formation of segment-specific body structures in the correct locations on the body.
Answer:
Megaspore—2n.
Explanation:
Angiosperms are the fruit bearing plants and reproduce by the process of sexual reproduction. The chromosome number are specific at each stage of the cell cycle of the angiosperms.
Microspores , egg are haploid. Zygote is diploid in nature. Megaspores get germinate into the female gametophytes and these are haploid in nature. Megaspores are also haploid in angiosperms.
Thus, the correct answer is option (b).
The correct answer is that "the T cell enters a state of anergy".
The activation of T cells requires two signals: (1) antigen specific signal presented by an antigen presenting cell (either a macrophage or a dendritic cell) that activates t cell receptors and (2) co-stimulatory signals that is not antigen specific but rather found in the plasma membrane of the antigen presenting cell (i.e. CD28). In the absence of a co-stimulatory signal, the t cell will enter a state of anergy or the inability to produce an immune response toward an offending antigen.
Answer:
Below
Explanation:
4) An endoskeleton is an internal skeleton made out of mineralized tissue that is attached to muscles as well as enabling movement.
5) An exoskeleton is the external skeleton that supports and protects an animal's body. As an example, a snail's shell is an exoskeleton
Hope this helps :)
